如何使用日期解析時區

Question

我們如何獲得日期工具來解析時區字符串？

$>date -d "2018-02-21T02:22:33.221" "+%Y-%m-%dT%H:%M:%S.%3N %Z"
2018-02-20T14:22:33.221 EST

但

$>date -d "2018-02-21T02:22:33.221 EST" "+%Y-%m-%dT%H:%M:%S.%3N %Z"
date: invalid date `2018-02-21T02:22:33.221 EST'

這是本地信息：

$>uname -r
2.6.32-696.13.2.el6.x86_64

$>date
Tue Jan 16 09:58:52 EST 2018

$>date --version
date (GNU coreutils) 8.4
Copyright (C) 2010 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by David MacKenzie.

Answer 1

ISO8601允許您用空格替換T 只要做到這一點，您的命令就可以正常工作：

# date -d "2018-02-21T02:22:33.221 EST" "+%Y-%m-%dT%H:%M:%S.%3N %Z"
date: invalid date `2018-02-21T02:22:33.221 EST'

但：

# date -d "2018-02-21 02:22:33.221 EST" "+%Y-%m-%d %H:%M:%S.%3N %Z"
2018-02-21 10:22:33.221 MSK

Answer 2

date -d不是date +format ，它只能接受來自man date一些字符串

  -d, --date=STRING display time described by STRING, not `now' DATE STRING The --date=STRING is a mostly free format human readable date string such as "Sun, 29 Feb 2004 16:21:42 -0800" or "2004-02-29 16:21:42" or even "next Thursday". A date string may contain items indicating calendar date, time of day, time zone, day of week, relative time, relative date, and numbers. An empty string indicates the beginning of the day. The date string format is more complex than is easily documented here but is fully described in the info documentation.